Mi4 Deletes All Google Accounts Every Night After Update

Hello all,
as the title says since I updated to the latest miui (6.7.1.0 KXDCNCH) all my google accounts are deleted every night, and I wake up without contacts, emails and so on. Any ideas why this happens? If you need details ask please.

Thank you for your answer, Dawson19. I managed to find the source of the problem; it was the automatic backup ocurring every night. Backing up the google account manager is enough to lose all the accounts. Can you confirm this happens for you, too?
I have opened a bug here http://en.miui.com/thread-157375-1-1.html